Flat or "pancake" motors have been employed in numerous applications where length is a critical factor. In general, axial air gap "pancake" armature designs provide the shortest length motor profiles available and are characterized by axial air gap, printed, stamped or wire wound armatures and axial or radial oriented brush/spring assemblies for axial or radial commutation.
While known motors of this type have proved themselves beneficial for their desired purposes, today there are many applications where reduction of length need be optimized even further. For example, this is the case with motors used in many automotive applications, such as in radiator and condenser cooling modules, as well as window lifts, blower assemblies and the like. Engine compartments and body panels in automobiles are constantly decreasing in available volume while passenger space is constant or increasing. Consequently, minimizing length and weight, as well as costs, while maximizing power output are important criteria for not only automotive applications but also other applications of such motors, as, for example, aerospace, industrial and other commercial applications. It is to be understood, therefore, while the flat motor of reduced length of this invention is disclosed in its relation to automotive applications, it may also be employed in a wide variety of aerospace, industrial and commercial applications.
Accordingly, it is the purpose of this invention to provide a motor having reduced length and weight, as well as minimized costs of manufacturing, while increasing efficiency and output power. In the past, in order to reduce motor length, alternatives such as double cage magnet structures, that is, two individual magnet lengths, bearing journals located within the stamping, and radially oriented brush holder assemblies located between magnet poles on wire wound armature designs with standard commutation and rear radial exit leads, have been employed. There exists, however, a need to provide a motor embodying these features and others in an even more optimized manner. The present invention fulfills such needs.